Note: Remember that any Page Rule subdomains must be resolving to Cloudflare in order to work. Subdomains that don't exist in DNS or aren't being directed to Cloudflare won't have Page Rules applied, so you'll need an "Orange Clouded" DNS record for the subdomain for the Page Rule to work.

Forwarding examples:

Example forwarding to Google+:

Imagine you have a Google+ profile and you want to make it easy for anyone coming to get to simply by going to a URL like:

Once you have created the pattern that matches what you want, click the Forwarding toggle. That exposes a field where you can enter the address I want requests forwarded to.

https://plus.google.com/yourid

If I enter that in the forwarding box and click the Add Rule button within a few seconds any requests that match the pattern I entered will automatically be forwarded with a 302 Redirect to the new URL.

Advanced forwarding options:

If you use a basic redirect, such as forwarding the root domain to www.example.com, then you lose anything else in the URL. For example, you could setup the pattern:

example.com

And have it forward to:

http://www.example.com

But then if someone entered:

example.com/some-particular-page.html

Then they'd be redirected to:

www.example.com

Not where you'd want them to go:

www.example.com/some-particular-page.html

The solution is to use variables. Each wildcard corresponds to a variable when can be referenced in the forwarding address. The variables are represented by a $ followed by a number. To refer to the first wildcard you'd use $1, to refer to the second wildcard you'd use $2, and so on. To fix the forwarding from the root to www in the above example, you could use the same pattern:

example.com/*

You'd then setup the following URL for traffic to forward to:

http://www.example.com/$1

In this case, if someone went to:

example.com/some-particular-page.html

They'd be redirected to:

http://www.example.com/some-particular-page.html

NOTE: Traffic must be passing through Cloudflare for Page Rules to work, if you are using Cloudflare for DNS only then Page Rules will not be active.